A bomb blast in western Afghanistan killed two Afghan civilians and wounded 17 others on Saturday, officials said.

The remote-controlled bomb was placed on a bicycle and went off on a road between Herat and that city's airport, said Noor Khan Nekzad, the spokesman for the province's police chief.

The blast killed two Afghan civilians and wounded 17 others, said Abdul Hakim Tamana, chief of health department for Herat province

There were no Afghan or Western officials on the road at the time of the blast, Nekzad said.

Western Afghanistan, which borders Iran, is relatively quiet in comparison to the country's south and east, where Taliban-led insurgents and other militants battle U.S., NATO and Afghan government forces. But the region has seen an increasing number of attacks over the last year.

In eastern Afghanistan, insurgents attacked a police post on Friday night, leaving one police officer dead and two wounded, officials said.

Some 30 militants using heavy machine guns and rocket-propelled grenades attacked the police post in the Sirkanay district of Kunar province, about one mile from the Pakistan border, said Gen. Abdul Sabor Alluhyar, province's deputy police chief.

Also Friday, a mortar round landed on a U.S. military outpost in the same province, wounding 12 civilian Afghan workers and two Afghan soldiers, NATO's International Security Assistance Force said.

"ISAF Forces immediately responded by providing medical assistance. All were treated at nearby ISAF medical facilities," the statement said.